Dynamic Transmission Performances of Alumina and Mullite Refractory Ceramics in Microwave High-Temperature Heating

2016 ◽  
Vol 35 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Xiaobiao Shang ◽  
Junruo Chen ◽  
Jinhui Peng
Keyword(s):  
Microwave Heating ◽  
Power Transmission ◽  
Peak Shift ◽  
Transmission Peak ◽  
Temperature Range ◽  
Microwave Transmission ◽  
Power Transmission Coefficient ◽  
Mullite Refractory ◽  
Refractory Ceramics ◽  
Temperature Heating

AbstractThis paper proposes an analytical approach to optimize the thickness of refractories for achieving maximum microwave power transmission in microwave heating based on the analysis of power transmission coefficient (PTC). The microwave PTCs of alumina (Al2O3) ceramics over the temperature range of 22–1,379°C at 2,450 MHz, mullite ceramics in the temperature range of 27–1,027°C at 2.45 GHz and 400–1,300°C at 915 MHz are studied. The results show that there are several transmission peaks in the PTC patterns. The transmission peak amplitude depends sensitively on the thickness of the refractory and the peak shifting towards a smaller thickness as the temperature of the refractory increases. We also show that high microwave transmission can only be achieved in a refractory with a small thickness corresponding to a slight transmission peak shift in the entire microwave heating (less than one eighth wavelength in the refractory).

scholarly journals Equivalent circuit modeling in GaN wireless power transmission including stray inductance and capacitance by measuring radiated emission

2022 ◽  
Author(s):  
Toshihide IDE ◽  
Mitsuaki Shimizu ◽  
Noriyuki TAKADA
Keyword(s):  
Power Transmission ◽  
Supply Voltage ◽  
Peak Shift ◽  
Stray Capacitance ◽  
Resonance Model ◽  
Series Resonance ◽  
Equivalent Circuit Modeling ◽  
Destructive Measurement ◽  
Output Capacitance ◽  
Radiated Emission

Abstract We establish the method for estimating the stray elements of the GaN-WPT circuit by measuring the radiated emission around the GaN switching device. By controlling the circuit supply voltage, the spectrum peak shift due to the output capacitance of the GaN-HEMT is observed. It is found that these peak shift characteristics include the influence of both the stray wire inductance and stray capacitance. By the fitting using the series resonance model, the value of the stray inductance and stray capacitance can be estimated in the non-destructive measurement in the GaN-WPT circuit.

Electromagnetic waves transmission performance of alumina refractory ceramics in 2.45 GHz microwave heating

2019 ◽  
Vol 45 (17) ◽  
pp. 23493-23500 ◽  
Author(s):  
Xiaobiao Shang ◽  
Di Zhai ◽  
Fucheng Zhang ◽  
Cong Wei ◽  
Junruo Chen ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Electromagnetic Waves ◽  
Transmission Performance ◽  
Alumina Refractory ◽  
Refractory Ceramics

scholarly journals Methods for synthesis of matching circuits for broadband radio devices with unstable load impedance

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 61-69
Author(s):  
I. A. Dubovik ◽  
P. V. Boykachev ◽  
V. O. Isaev ◽  
A. A. Dmitrenko
Keyword(s):  
Transfer Coefficient ◽  
Power Transmission ◽  
Synthesis Method ◽  
Synthesis Methods ◽  
Power Transfer ◽  
Load Impedance ◽  
Advantages And Disadvantages ◽  
Power Transmission Coefficient ◽  
Broadband Matching ◽  
Comparison Of The Results

The aim of this work is to select a synthesis method for a broadband matching circuit that provides maximum power transfer from a signal source to a load in the presence of a changing load impedance of a radio engineering device. To achieve this goal, an analysis of the main directions of designing broadband matching circuits (analytical, numerical, graphic-analytical synthesis methods) was carried out. Based on the results of a comparison of synthesis methods, their features (advantages and disadvantages) were indicated. The analysis of methods of synthesis of broadband matching circuits was carried out. For the analysis, the generalized Darlington method, the method of real frequencies, the structural-parametric synthesis method based on the T-matrix apparatus, and the graphic-analytical method based on the Volpert-Smith diagram were chosen). Using these synthesis methods, broadband matching circuits were obtained for various types of loads. Comparison of the results obtained was carried out according to several indicators: the level of the power transfer coefficient in the operating frequency range, the sensitivity of the power transfer coefficient to the change in the ratings of the elements of the matching circuit and the load impedance, provided that the number of elements of the matching circuit is no more than six. Based on the comparison and analysis, it was found that the most preferable synthesis method for solving the problem posed is the method of real frequencies. Its advantage is the use of a combination approach (iterative determination of the parameters of the resistance function with an analytical representation of the transfer function). Matching circuits obtained using this synthesis method provided the highest level of power transmission coefficient, as well as the lowest sensitivity value in a given frequency band for the considered types of loads.

Microwave transmission performance of fused silica ceramics in microwave high-temperature heating

2019 ◽  
Vol 45 (5) ◽  
pp. 6157-6162 ◽  
Author(s):  
Di Zhai ◽  
Cong Wei ◽  
Fucheng Zhang ◽  
Xiaobiao Shang ◽  
Junruo Chen ◽  
...  
Keyword(s):  
High Temperature ◽  
Fused Silica ◽  
Transmission Performance ◽  
Microwave Transmission ◽  
Temperature Heating ◽  
High Temperature Heating

The Investigation of Metamaterials by Measuring the Power of Transmission in the Terahertz Regime

2012 ◽  
Vol 571 ◽  
pp. 133-136
Author(s):  
Jun Luo ◽  
Ying Chen ◽  
Sheng Wu Kang ◽  
Xin Yu Zhang ◽  
Chang Sheng Xie ◽  
...  
Keyword(s):  
Power Transmission ◽  
Transmission Peak ◽  
Global Maximum ◽  
Transmission Properties ◽  
Maximum Transmission ◽  
Measured Power

We present the design and fabrication of metamaterials, and investigated the power transmission properties of the metamaterials in the frequency ranging from 1.04THz to 4.25THz. The measured results reveal a global maximum transmission peak at 2.52THz. We compared measured power transmission performances of four types of metamaterials microstructures, and analyzed their transmission differences.

scholarly journals Mathematical Simulation of Temperature Profiles within Microwave Heated Wood Made for Wood-Based Nanocomposites

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Xianjun Li ◽  
Yongfeng Luo ◽  
Hongbin Chen ◽  
Xia He ◽  
Jianxiong Lv ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Microwave Heating ◽  
Wood Surface ◽  
Temperature Profiles ◽  
Thickness Direction ◽  
Heating Method ◽  
Microwave Pretreatment ◽  
Microwave Transmission ◽  
Modify Wood

High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nanocomposites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased along the direction of microwave transmission when the unilateral microwave heating was applied, and the temperature difference along the thickness direction of wood was very significant; The temperature with wood firstly increased and then gradually decreased from the wood surface to interior when the bilateral microwave heating was applied. Compared with the unilateral microwave heating, bilateral microwave heating is a better microwave heating method for the more uniform wood microwave pretreatment.

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